DRS not always working

[drb1965 7]

during practice the, cross the drs line and message says drs available press the drs button and drs activates for a moment then deactivates.  Sometime it activates, sometimes it doesn't, sometimes you have to hold down the drs button, no pattern to it.

only happens in practice, during the race and quali it is fine

[Xyadas 0]

Well there's only three ways (bugs aside) for DRS to deactivate. The driver pushes the DRS button again, the brake pedal is pressed, or the car exits the DRS zone. The most plausible scenario (bugs aside again) is that the brake pedal is jittering without your input and causing the DRS to deactivate. Have you checked your calibration? Is the brake bar on the input graph in the controls menu jumping around a little bit on the bottom end?

And for some reason I neglected the fact that you mentioned it is fine in qualifying and race...soooo, nevermind, lol.

[drb1965 7]

Thanks for the tip, think my brake pedal is broken as it also appears to be "jittering" down the straight.  No wonder I can not get near the AI.